From OpenSCADAWiki
Besides this subsystem, the Control Interface also provides of the access checking per the control items and with logical dividing the permissions per subsystems for which there are automatically created the system groups, including this one — "Security". Currently any Control Node (TCntrNode) can have own access permition (ACL) which the Control Interface can use or save the compatibility before switching to it, and with saving the initial permissions on the subsystem root like to "root:DAQ"-0775.